Beta-carotene-rich orange-fleshed sweet potato improves the vitamin A status of primary school children assessed with the modified-relative-dose-response test

Am J Clin Nutr. 2005 May;81(5):1080-7. doi: 10.1093/ajcn/81.5.1080.


Background: Beta-carotene-rich orange-fleshed sweet potato (OFSP) is an excellent source of provitamin A. In many developing countries, sweet potato is a secondary staple food and may play a role in controlling vitamin A deficiency.

Objective: The objective was to determine the efficacy of daily consumption of boiled and mashed OFSP in improving the vitamin A status of primary school children.

Design: Children aged 5-10 y were randomly assigned to 2 groups. The treatment group (n = 90) consumed 125 g boiled and mashed OFSP (1031 retinol activity equivalents/d as beta-carotene), and the control group (n = 90) consumed an equal amount of white-fleshed sweet potato devoid of beta-carotene for 53 school days. All children were dewormed to exclude helminthic infection. The modified-relative-dose-response test for vitamin A status was conducted before and after intervention.

Results: The estimated intervention effect for the ratio of 3,4-didehydroretinol to retinol (DR:R) was -0.008 (95% CI: -0.015, -0.001; P = 0.0203), which indicated a greater improvement in vitamin A liver stores in the treatment group than in the control group. The proportions of children with normal vitamin A status (DR:R < 0.060) in the treatment group tended to increase from 78% to 87% (P = 0.096) and did not change significantly (from 86% to 82%) in the control group (P = 0.267). These proportions were not used to test the intervention effect or within-group changes because the study was powered to test the intervention effect on DR:R.

Conclusions: Consumption of OFSP improves vitamin A status and can play a significant role in developing countries as a viable long-term food-based strategy for controlling vitamin A deficiency in children.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anthropometry
  • Antioxidants / therapeutic use
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Ipomoea batatas*
  • Male
  • Phytotherapy*
  • Plant Preparations / therapeutic use*
  • Rural Population
  • Vitamin A Deficiency / blood
  • Vitamin A Deficiency / drug therapy*
  • beta Carotene / administration & dosage
  • beta Carotene / therapeutic use*


  • Antioxidants
  • Plant Preparations
  • beta Carotene